We will continue our studies of fertilization and spontaneous activition. We hope to determine when and how the parthenote gains the diploid state. Is there a recapture of a polar body? We will continue our study of hermaphrodism using the two strains of BALB/ cWT to produce chimeras. Half of these should be XX reversible yields XY combinations and thus produce workable numbers of hermaphrodites. As a corollary to our concept for the development of hermaphrodites by nondisjunction of the Y-chromosome during an early cleavage to produce XO and XYY clones, we would expect to find some XYY males. There is a great demand for XYY animal models for the human condition and we will search for these. We fully anticipate to identify the pheromone in the next few months and will then explore the inhibitor from femal@s and pheromones from other species. We will explore the possibility of using pheromones in control of wild populations of mice. We have developed a method to prepare the pigment layer of the retina to test our mathematical model for clonal distribution. We hope to apply this to the problem of X-chromosome inactivation. Bibliographic references: Anderson, Everett, P. C. Hoppe, W. K. Whitten, and G. S. Lee. 1975. In vitro fertilization and early embryogenesis: a cytological analysis. J. Ultra Res. 50:231-252. Hoppe, P. C., and W. K. Whitten. 1974. An albumin requirement for fertilization of mouse eggs in vitro. J. Reprod. Fert. 39:433-436.